February 3, 2023

Study Reveals Unexpected Effects of Toxoplasmosis in Wolves

2 min read

It is a well-known disease and dreaded by pregnant women. However, toxoplasmosis would have unexpected effects… in wolves.

Toxoplasmosis is a disease caused by a parasite transmitted by felines.
More than one third of human beings are infected by this parasite. It is, in most cases, benign except for immunocompromised people or the fetus. Hence the advice given to pregnant women to avoid direct contact with cats or to eat badly cooked meat.

In wolves, this parasite would have effects on their behavior: a wolf infected by Toxoplasma Gondii is more likely to impose itself as a pack leader. This is the result of a study conducted in the United States in Yellowstone Park, where researchers followed more than 200 wolves and about 60 cougars, which can transmit the parasite. Infected animals are more aggressive, more independent and more adventurous than their fellow wolves. These are traits of pack leaders. According to the researchers, wolves affected by the parasite are 46 times more likely to have a leadership role.

Toxoplasmosis linked to psychiatric disorders

The parasite is known to affect the brain. It tends to increase the level of dopamine and thus reduce the feeling of fear. Moreover, scientists have already observed this phenomenon in other infected animals such as rodents or hyenas. Studies have shown that toxoplasmosis tends to make them less fearful. For example, mice are no longer afraid of cats, or hyenas are not afraid to visit lions.

It is hard to say that the same conclusions can be drawn for human beings,
but, indeed, scientists are trying to understand what the impact of the parasite may be on human behavior. They have managed to show links between toxoplasmosis and certain psychiatric disorders such as bipolarity, schizophrenia or obsessive-compulsive disorders. The parasite would contribute to the development of these pathologies. But, for the moment, no formal proof of a link between the two has been established and researchers continue to study the mysteries of this disease.